Connect the temperature sensor with the enclosure and power up reef-pi.

Never connect or disconnect a temperature sensor from the enclosure while reef-pi is running. The audio jack connectors short the GND and +Ve pins during plugging/unplugging. This causes the Raspberry Pi to reboot. Always power down the reef-pi controller and unplug the input power before connecting or disconnecting a temperature sensor.

Once up and running, make sure temperature capability is enabled. If not, enable it under the settings section of the configuration tab. Reload reef-pi every time settings are updated.

Refresh your browser after reef-pi is reloaded and the temperature tab should appear. Navigate to the temperature tab and create a new temperature controller by clicking on the "+" button. A new temperature item should be available from the Sensor drop-down (DS18B20 sensors always have a name starting with 28-). The enable option represents whether reef-pi will check this sensor or not. Once enabled, the Check Frequency option represents how frequently (seconds) reef-pi should check for sensor value. Next, the alert and control option allows sending an alert if the temperature goes outside a specified range or turning on heater or cooling devices. For this example, we'll just enable sensor monitoring.

Once created, the new temperature controller will appear in the list. We can now use this new temperature control to chart the sensor data.

Charts & Dashboard

reef-pi provides two types of charts for each temperature controller. The first type of chart is simply known as temperature which indicates the latest temperature at check interval granularity. reef-pi will store one days worth of data when check interval is set to 1 minute (1440 values).

The other temperature chart is known as tc or temperature controller. Temperature controller chart stores hourly average temperature along with heater and cooler usage (in seconds) for past thirty days.

Configure the main dashboard to enable both types of temperature chart for the new sensor.


Click on update to save the new dashboard configuration and then click on Back to dashboard. You should see the temperature charts in the main dashboard now. The example images are taken from a controller running for a few days. For new builds, the charts will be have limited data.

Adafruit IO

Other than the in-controller dashboard, reef-pi also allows data logging to the Adafruit IO data service. You can enable in the telemetry section under the configuration tab. You'll need to specify your username and AIO Key. Once enabled, reef-pi will start emitting data to reef-pi will automatically create a feed named the same as temperature controller name and with a tc- prefix. This feed will hold the temperature data and can be used to create a dashboard in The following is an example temperature dashboard using integration.

Temperature is one of the key requirement for reef aquariums. With this feature, reef keepers will be able to understand and explore daily and seasonal aquarium temperature variation while having an extra safety net during heater failure.

In the next guide, we'll build the necessary automation for stabilizing the second most important parameter of reef aquariums, salinity.

This guide was first published on Sep 25, 2018. It was last updated on Sep 25, 2018.

This page (Configuration & Testing) was last updated on Jan 25, 2021.